The ATI Radeon HD 5870 cannot pull enough power directly through the motherboard to work properly, as other expansion cards do. Instead, this video card needs to have a direct connection to your power supply through the connector on the back of the card. Once the card is connected into the power cable, it receives enough electricity to work properly and not cause any power-related issues.
Instructions
1. Power off your desktop. Disconnect all cables on your computer tower. Remove your case's cover. If you cannot unscrew the side panel of your case cover, try looking for a release button or latch on the computer.
2. Detach the slot cover from the back of your case.
3. Slide the Radeon 5870 HD graphics card into the PCI-E slot on your computer's motherboard.
4. Connect the power cable into the power connector on the video card. The Radeon video card will not work properly if you do not connect the power cable to the card.
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